| The backport-util-concurrent software has been released to the public domain, | |
| as explained at: http://creativecommons.org/licenses/publicdomain. | |
| Acknowledgements: backport-util-concurrent is based in large part on the public | |
| domain sources from: | |
| 1) JSR166, | |
| 2) package dl.util.concurrent, | |
| 3) Doug Lea's "collections" package. |